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TELEGRAPHY.

No. 481,247. Patented Aug. 23, 1892.

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No. 481,247. Patented Aug. 23, 1892.

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TBLBGRAPHY.

No. 481,247. Patented Aug. 23, 1892.

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TELEGRAPHY.

No. 481,247. Patented Aug. 23, 1892.

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WITN ESSES' NITED STATES PATENT Ormes.

JAMES G. SMITH, OF NEV YORK, N. Y.

TELEGRAPHY.

SPECIFICATION forming part of Letters Patent No. 481,247, dated August23, 1892.

Application filed November 2, 1889. Serial No. 329 ,087. (No model.)

To all whom it may concern:

Be it known that I, JAMES G. SMITH, of New York, in the county of NewYork and State of New York, have invented certain new and usefulImprovements in Telegraphy; and I do hereby declare the following to bea full, clear, and exact description of the same, reference being had tothe accompanying drawings, forming a part of this specification, and tothe figures and letters of reference marked thereon.

The maintenance of private telegraph-lines between persons in remotecities or districts is enormously expensive, considering the limited usethat is made of such lines, there seldom being a day in which all thebusiness transacted over a given line occupies the line more than anhour in the aggregate.

The object of my invention is to provide a system by which any one of anumber of persons in one cityor district may establish communicationwith any one of a number of personsin a remote city or district over oneofa series of main lines at comparatively small expense to theindividual, with the same privacy as can be secured by the use of aprivate line and without Aret'lniring any hand manipulation except onthe part of the person calling and of the person being called, all elsebeing accomplished automatically by suitable apparatus provided for thepurpose:

Generally stated, my invention involves the use of a series of mainlines extending between the remote cities or districts sought to be putin communication,a central station at each terminal of said main lines,a series ot` subscribers circuits in each cityor district, a series ofswitching apparatuses at each central station, one for each subscriberscircuit, adapted to automatically establish connection with any one ofthe series of main llnes that happens at the time to be idle upon aproper signal from a local subscriber; another switching apparatus ateach central station for responding to signals from the distant city orstation over any one of the main lines and automatically connecting saidmain line with the local subscriber with whom the distantsubscriberwishes to communicate, and an indicating apparatus at each subscribersstation for indicating that communication `cation with a subscriber inthe remote city or district.

It further involves the use of auxiliary apparatus for increasing thecapacity of the receiving apparatus at the central station, and it alsoinvolves the use of separate means by communication between thesubscribers and the central station.

Having thus given a general notion of my improved system, I will nowproceed to describe the same in detail with reference to the particularinstrumentalities shown in the accompanying drawings.

Referring to said drawings, Figure l represents the apparatus at themain office of the system at one city, as New York, as shown at A, and asub-station at the same city, (shown at C.) The apparatus, as shown inthis ligure, is in the position of rest, ready for operation. the mainoiiice in a distant city-say Bostonas shown at B, and two sub-stations Dand E in the same city, Boston, both sub-stations being located in theinstance shown on the same local-circuit wires connected in series. Thesub-stations are thus shown for the purpose of illustrating thedifference in the apparatus used when only one sub-station is placed ona local circuit, as in Fig. l, and where two or more sub-stations areplaced on one local circuit, as in Fig. 2. The apparatus in Fig. 2 isalso shown as it appears when in a position of rest, ready foroperation. Fig. 3 shows the same apparatus as Fig. l, but with a portionof it in operated position. Fig. 4 shows the same apparatus as Fig. 2,but with a portion of it in operative position. Fig. 5 shows anarrangement by which the capacity Fig. 2 shows similar apparatus at IOOof a portion of the apparatus at a main office can be increased. Itfurther shows a modification of the sub-station apparatus Where morethan one such sub-station is located on the same local circuit. Theapparatus in this figure is also shown in a condition of rest. Fig. 6shows the same apparatus as Fig. 5, but as it would appear whenoperated. Fig. 7 is a detailed illustration of the construction of aconvenient form of the dial used at each sub-station for the purpose ofcontrolling the automatic selection of the desired sub-station by theapparatus at the "distant main office. Fig. S is an end View of theframe at the main office that supports the sets of contact-points, andalso of the moving parts of the apparatus. Fig. 9 is a perspectivesectional view of the same frame, showing a few of the sets ofcontact-points placed around the frame. The only difference in any ofthe frames is in the arrangement and number of the contact-points. Fig.10 is a perspective sectional View of the frame 1, Figs. 5 and G.

Similar letters and figures of reference in the several figures indicatethe same parts.

Referring now to Fig. 1, the apparatus therein shown consists of two ormore circular frames 1, 1, and 1b, those marked 1 and 1 being in everyrespect entirely alike and of any desired number and being referred toas 1 and 1 simply for convenience of description. These frames have amechanicallydriven shaft 2, passing through but not connected with eachframe, the shaft or shafts being kept constantly rotating by electricmotor, as herein shown at 4, or by clockwork, weights, steam, hand,water, or other power. A band-wheel is herein shown at 3 attached to theshaft.

Attached at intervals around the frames 1 and 1 are a series of sets ofinsulated contact-points, formed of metal strips, some rigid and theothers iiexible, all the sets being similar with the exception of oneset, the similar sets (marked S on Fig. 9) cach representing theconnections to one of the main or trunk lines and the various strips andsprings so arranged as to operate jointly to form connection by movingparts operated by the revolving shaft with that sets particular 'mainline, and also to reserve that line to the substation then using it, andalso to bring into use the main battery upon said line, as will all bemore particularly described hereinafter. The dissimilar set (marked T onFig. 9) has its strips and springs arranged diiferently, being the homeset, at which the apparatus automatically comes to a stop, with the eX-ception, of course, of the shaft. Each frame marked 1 and l has asimilar equipment of these sets of contact-points, and on each frame thenumber of such sets will correspond with the number ot' main or trunkwires employed in the system. The number of these frames 1 and 1L at amain office, together with the whole apparatus for each, as shown at 1,corresponds to the number of local sub-station circuits at that end ofthe system, and the number of sets of contact-points upon each framecorresponds to the number of main Wires employed, as aforesaid. Thenumber of frames 1", however, corresponds to the number of main wiresand not to the number of sub-stations, (as in the case of the frames 1and 1,) and the number of sets of contactpoints on each of the frames 1bcorresponds to the number of substation circuits (instead of to thenumber of main wires, as in the case of the frames 1 and 1*) that is tosay, there is one frame 1b at each end of each main wire, and on each ofthese frames are sets of contact-points corresponding in number andconnected severally to the local sub-station circuits, the saidcontact-points forming the sets so arranged as to operate jointly withthe moving parts when operated by the revolving shaft to form connectionto that sets particular sub-station circuit.

Rigidly attached to the shaft 2, Fig. 1, and revolving with it andwithin (but not attached to) each of the frames 1 and 1 is a disk 5,provided with holes in its face. In close proximity to this disk is acylinder orsleeve G, through which the shaft 2 runs. Pivoted upon suchcylinder or sleeve and insulated therefrom is an armature-bar 9,provided at one end with a stud or projection 10, so arranged as toengage with the holes in the rotating disk 5, thereby rotating sleeve 6and the attachments thereto, and having at its other end projections, asshown at 11,12, and 13, insulated from each other, as shown, and theextreme one 13 projecting each side of the armaturebar 9. Also mountedupon sleeve 6 are the magnet 7 and the retractile spring S, botharranged to operate armature-bar 9. The crossbars or projecting arms 11,12, and 13 are of such lengths and so arranged as to engage severallywith their respective series of strips and springs forming the sets ofcontact-points 14, 15, 1G, 17, 18, 19, 20, 21, and 22, Fig. 1,when inoperation. Also mounted upon this sleeve 6 are the metalcommutator-strips 23, 24.-, and 25, which are insulated both from thesleeve and from each other. One of these commutator-strips (shown hereinat 24) is of suiicient width to receive two brushes upon its surface,the others having only one brush each, as shown. These lattercommutators 23 and 25 pass completely around the sleeve; but the one 24,having two brushes bearing upon it, is only a segment of a cylinder, theremainder of the cylinder being composed of insulating material. Themetallic segment 24. is placed at such a point that the brushes restupon it only when the projecting arms 11, 12, and 13 of the armature-bar9 are at the home set of contact-points, (shown at T.) The brushes areshown in this figure at 20, 27, 28, and 29. They are formed of metallicsprings and are supported independently of said sleeve. These brusheshave connections by wire, as shown, brush 2G with battery 30, and alsowith battery 31, and from the latter to switch 32,

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thence on through magnet 37 to `key 38, and thence by switch 39 tosub-station C. Brush 27 connects through battery 30 to brush 26, brush28 with earth at 46, and brush 29 with the sub-station C, all as shown.

In passing I would state that for the purpose of enabling the mainofficeAto communicate locally with the sub-station C, if at any timedesirable, there is provided, as Shown, battery 35, with earthconnection 36, and further connection to stud 34 by switch 32, whichwhen connected forms circuit for battery 35 through magnet 37 and key 38to switch 39, and when the latter is thrown upon the stud 41 the circuitis completed to substation C. The local sounder-circuit for inag net 37is completed by armature 48 with stud 110, sounder-magnet 47, battery50, and earth 46 and 51. At the frame 1b there is also shown the shaft2, supplied with its fixed disk 59,similar to disk 5 at frame 1andsleeve 60, the latter having mounted on it, as shown, the magnets 61 and62, having a common core, the retractile spring 63, and the insulatedarmature-bar 64, provided With its stud 65 at one end, and itsprojections 66, 67, 68, and 69 at the other end so arranged as tooperate, when desired, the contact-points 70,71, 72, 73, 74, 75, 76, 77,78, 79, 80, and 81. The contact-point 80, however, is not directly inline with the other contact-points of the set, but is placed in advanceof them, so that the projecting arm 69 will form contact with it justprior to forming contact With 81. Also mounted upon this sleeve 60, butinsulated from it and from each other, are the metalliccommutator-strips 85, 86,87, 88, 89, and 90, one of which (shown in thisinstance as 85) is only a small segment of acylinder, the remainderbeing composed of insulation and so arranged that the brush of thiscommutator bears upon it to form connection only when the projections66, 67, 68, and 69 arrive at the set of contact-points marked Y, whichis the set at which they normally rest When the apparatus is not beingoperated. This set of contact-points Will hereinafter be referred to asthe home set. Brushes similar to those described for frame 1 are shownhere at 91, 92, 93, 94, 95, and 96, bearing upon their respectivecommutatorstrips. These brushes have connections by wire, as shown andas will be more fully explained hereinafter.

The apparatus at sub-station C consists, as shown in Fig. l, of a dial,which is more clearly shown in Fig. 7 and described in detailhereinafter. There is also provided, as shown at Fig. 7, a shortmetallic plug for insertion in the holes in the dial, so .shaped thatits head Will project sufficiently to allow the arm 425 to pass over it,but at the same time touch it sufficiently to make contact therewith.There is also provided at C, as shown in Fig. 1, a relay-magnet 102,with its armature, local sounder, battery, and circuit-wires, as shown;also, key 103, rheostat 104, switch 105, with its studs 106 and 107,Withwire connections running to earth at 108, as shown.

The main -line batteries are shown at 112 on Fig. 1, representing oneterminus of the system, and at 256 on Fig. 2, representing the otherterminus. Each main or trunk line is similarly equipped With batteries.

In Fig. 2, representing the distant end of the main lines-say Boston-theapparatus shown at frame 1) at the main office B, is the same as shownat A, Fig. 1, at frame 1,.With the exception of slight changes in theauxiliary parts of the frame, such changes being required when two ormore sub-stations are placed on one local circuit in series, leading tosuch frame. In this latter case the substations may be equipped, asshown at D and E, Fig. 2, such equipment being the same as shown at C,Fig. 1, With the addition of apparatus for the purpose of enabling anyone substation When operating the line to cutout all other sub-stationslocated on the same local circuit with itself, thereby reserving theline privately to itself and avoiding interruption by others While sooperating. This additional apparatus consists of an electro magnet,(shown at 220 at 1),) With its armature 213 centrally pivoted, the endsof the armature insulated from each other and having its actioncontrolled by the stops 215, 217, and 218, one end of said armatureprovided With a metallic strip on the upper side, insulated from thearmature, as shown at 216; also, rheostat 221 and switch 210 With itsstuds 211 and 212 with their connections, as shown. On each substationlocal circuit having more than one sub-station included therein theequipment is the same With the addition of a battery and groundconnections at the last station farthest from the main office, as shownat 254 and 255 at E.

The apparatus represented in Fig. 5 illustrates that feature of theinvention Which comes into use when the number of sub-station circuitsis greater than can be conveniently provided for by sets ofcontact-points on any one frame 1b or 1bX-that is to say, assuming thenumber of sub-station circuits to be five hundred, and assuming, also,that the size of the frame lb or lhX Will not Couveniently accommodatemore than one hundred sets of contact-points, then the apparatus hereshown provides for the other four hundred or any larger number.

The sub-station apparatus as shown in Fig. 5 is a modification of thesub-station apparatus shown in Figs. 2 and 4, the batteries thereinhaving their poles in series, While in Figs. 2 and 4 they7 are opposed.The positions of the resistances are also transferred to the extreme endof the circuit, as shown. Frame l, Fig. 5, and its auxiliary parts arethe same as shown in Figs. 2 and 4. Frame 1c is similar to frame 1b or1b of Figs. 1, 2,3, and 4, With the addition of one or more sets ofcontact-points arranged as shown at'Z.

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The object of this set or sets of contact-points (shown at Z) is toenable connection to be made from the main line through the armature-barat frame 1c to the auxiliary switch or switches F, as best shown in Fig.6. If de sired, therefore, the whole or any portion of this frame 1Ccanbe equipped with these sets of contact-points Z, connecting withswitches F, so that by placing one hundred such sets Z upon this frame1C one hundred auxiliary switches F can be brought into use, each switchF representing one hundred or more sub-stations, thus showing the almostunlimited capacity of the system. This auxiliary switch F consists ofasimilar frame, (marked 1d,) provided with sets of contact-pointsarranged, as shown at X, on frames 1', Figs. 1, 2, 3, and 4,corresponding in number to the number of sub -stations to beaccommodated on this particular switch. lt also has a set ofcontact-points arranged as shown at XV, representing the home set ofthat switch.

The shaft, sleeve, disk, armature-bar, ttc., are the same as in 1C; butthe commutator strips and brushes, while of the same construction, areless in number, as shown.

The detail view of Fig. 7 represents the dial placed at each of thesub-stations, the perforations in the metallic plate being shown at 419,the electro-magnet at 420, and its armature-bar at 421, the latterhaving a retractile spring 422 and ratchet-pawl 423, engaging with theratchet-wheel 424. The number of teeth or notches in the ratchet-Wheelcorresponds to the number of holes in the face of the plate, which isrigidly attached to the short shaft 427, supporting the metallic arm425, having a handle, (shown at 426.) The brush 428 also bears upon theshaft 427. A limited number of the holes 1 to 4, immediately succeedingthe zero-point of the dial, represent the several auxiliary switches atthe distant citysuch as shown at F, Figs. 5 and G-and the other holes 1to 12 represent the sever al sub-station circuits at the distant city.The handle 426 is employed to bring the arm around by hand to Zero-pointafter use.

Havingnowdescribed theseveralparts,1will proceed to describe theiroperation. Assuming that the operator at the station C, which issupposed to be at New York, desires to communicate with station E, whichis supposed to be at Boston, the operation would be as follows: First,he would insert the brass plug 430, Fig. 7, in the hole in hisdial-plate 419, represent-ing the number of the local circuit at Bostonupon which station E is located.

-lle would then throw switch 42, Fig. 1, onto point 44, as shown in Fig.3, and throw open switch 105 until connection with substation E has beencompleted, as will be presently described, when he would close saidswitch 105 again. The throwing of switch 42 onto point 44 would openanother avenue for the current of battery 30, which has heretofore beenlocally energizing magnet 7 through brushes 26 and 27 andcomrnutator-strips 23 and 24 with their wire connections to magnet 7, asshown, forming the complete local circuit of this battery 30. The resultof thus weakening this local circuit is that the retractile spring 8 isenabled to overcome the magnet 7 and withdraw its end of thearmature-bar 9, thereby bringing forward the other end, which isprovided with the stud 10. This stud 10 then engages with one or theother of the holes in the disk 5, which is rotating by the movement ofthe shaft 2, to which it is rigidly attached, and the projecting arms11, 12, and 13 at the other end of the armaturebar 9 leave thecontact-points 14 and 16 of the home set T, and 13 engages in itsrotation with the contact-points 22 successively of each set until saidarm 13 arrives at the first set connected with a main wire not in useforinstance, the set S, Figs. 1 and 3. Meanwhile the sleeve G, togetherwith the parts attached to it, revolves wit-h said disk, removing thesegmental commutator-strip 24 from contact with the brushes 27 and 2S,thereby breaking the local circuit of battery 30 and also breaking theearth connection 46 from circuit of battery 31. The circuit path of thisbattery 31 therefore now passes by brush 26 and commutator-strip 23through magnet 7 to proj ection 13 of armature-bar 9 bywires, as shown,and thence to wire connected with the contact-point 22, therebyproviding a ground at 84 at frame 1b for battery 31, as follows: downcontact-point 21, up contact-point 20, thence to contact-point 57 offrame 1, and up contactpoint 56, thence in a similar manner through anyother frames in the circuit, and finally to contact-points 73 and 74 tothe earth 84. This circuit when so completed brings the apparatus to theposition shown in Fig. 3 by energizing magnet 7, which attracts the bar9, and thus withdraws stud 10 from disk 5 again, thereby freeing it fromthe motion of the continuously-rotating shaft 2, and the armaturebar andits connected parts stop with the pro-V jecting arms 11, 12, and 13,engaged with the contact-strips 17, 18, and 20, as shown. The result ofthis new position is, first, that the connection with the earth at 84 ismaintained by the projecting arm 13 bearing against contact-point 20,instead of 22, at the same time that it presses contact-point 2O awayfrom contact 2l,thereby preventing any othersubstation from formingconnection with this particular main line, and it is evident that thecontact-points 22 and 2O and the projecting arm 13 must be so relativelyadjusted that 13 engages with contact-point 20 before leavingcontact-point 22 to maintain the circuit of battery 3l through magnet 7unbroken; secondly, the result of this new position is that theinsulated arm 12, pressing the contactpoint 18 away from contact-point19, breaks the connection of the main line at this point from the ground83 of frame 1W; thirdly, the result is that the main battery 112 isthrown into the main-line circuit formed as follows: from earth 108,Fig. 3, at sub-station C, through the dial, magnet, and otherinstruments at that station to brush 29 and commutator-strip 25, thenceto projecting arm 11, which is now pressing against contactpoint 17, andthence to battery 112'and main line, as shown, whence it travels to thedistant end of the main wire, Boston, (shown at Figs. 2 and 4, (where itcomes in down coutact-point 129 of frame 1X, up contact-point 130,thence through any number of frames 13X,by contact-points 164 and 165,andfinally to frame 1M, by brush 205, commutator-strip 199, throughmagnet 171, thence to commutator-strip 200, and brush 206 tocontact-points 181 and 180. and thence to ground at 192, and the resultof the circuit so formed is to energize magnet 171, which is so arrangedas to neutralize the magnet 172, locally energized, as shown, allowingthe retractile spring 173. to withdraw its end of the armature-bar 174and bring forward the other end bearing the stud 175, which then engageswith the disk 169. As this disk is constantly rotating on themechanically-driven shaft 113, the sleeve and its attachmentsconsequently also rotate, and the projecting arms 176 and 177, havingbeen withdrawn from engagement With the contact-points 181 and 184 ofthe home set Y, Fig. 2, the ground connection of the main line is brokenat this point, but is maintained effectively, nevertheless, by theprojecting arm 179 engaging with the contact-point 185, as follows:vrlhe contactpoint 181, relieved of the pressure of the projecting arm176, bears against contactpoint 182, and the circuit then passes up thiscontact-point to brush 203 and commutator-strip 197, thence by wire, asshown, to projecting arm 179, which is bearing against contact-point185, up which it passes to earth at 194. rlhis is maintained only solong as the local circuit is energizing the magnet 172 by the contact ofbrush 202 with the segmental commutator-strip 196, and by the time thiscommutator-strip has passed from the brush by the rotation of the sleevethe projecting arm 179 passes beyond the contactpoint 185. Consequentlythere is now no cu rrent passing through either of the two magnets 171and 172, and the retractile spring 173 continues to hold the stud 175engaged with the disk 169, thereby continuing the rotation of thesleeve, causing the projecting arm 179 to bear successively uponcontactpoints 190 and 191 of each ot' the sets of contact-points placedaround the frame lbx, bearing against 190 before reaching 191, (in thesame Way as described heretofore ot' contactpoints 80 and 81,Figs. 1 and3,) and on reaching 190 of the set X, completing the main-line circuitto earth at 193, Fig. 4, thereby energizing the electro-magnet of thedial at the station C at New York, drawing forward its armature 421,Fig. 7. On leaving the contact-point 190, by the continued rotation ofthe apparatus, as described, the inain-linecircuit is again broken, thearmature of the dialmagnet at station C is released, and is drawn backagain by the retractile spring 422, Fig. 7, thereby moving theratchet-wheel 424, Fig. 7, one tooth by the pawl 423, Fig. 7, moving thearm of the dial one hole. Immediately after leaving 190, Fig. 4, theprojecting arm 17 9 engages with the contact-point 191, but passes fromit to the other succeeding sets, repeating the same engagements with the4contact-points 190 and 191 of each set until the arm 17 9 reaches theset corresponding to the number of the holes in which the plug is placedat station C, at which time the arm of the dial at C will have engagedwith the inserted plug, thereby grounding the main line at 429, as shownin Fig. 3, thus cutting out the rheostat 104 from the circuit, thusincreasing the strength of the main battery 112 by exactly theresistance that has beenintroduced by the rheostat 104, and whichresistance is such that when so removed the increased currentwillenergize the magnet 171 at frame 1b at Boston, thereby withdrawing thestud 175 from the disk 169, causing the sleeve and its attachment tostop at that position wit-h the projecting arms 176, 177, and 178 toform contact with the contact-points 186,187, and 189 of set X, as shownat Fig. 4, causing the following simultaneous changes: hecontact betweenthe projecting arm 179 and the contact-point 191 is broken, therebybreaking the main-line circuit atthat point,butnot,however, until a newavenue is formed for it, coming in through the battery 256, Fig. 4,thence by wire, as shown,to brush 204, thence to connmutator-strip 198,and thence by wire, as shown, to projecting arm 176, which has formedconnection with contact-point 186, whence it is continued by wire, asshown, to contact-point 125 of set T at frame 1, which is in contactwith the projecting arm 122 at frame 1, Fig. 4, whence it is continuedby wire, as shown, to commutator-strip 136, thence by brush 140 and bywire, as shown, to dial-magnet at station D, thence to magnet 226, key227, switch 229, contact-stud 230, and thence in a similar mannerthrough any other substations located upon the same sub-station circuit,finally terminating at the last station upon this local sub-stationcircuit, as represented at E, where it gets its ground, as shown atearth 254. It will be seen that the mainwire circuit as now formed doesnot include the magnet 171 offrame 1M; but the armaturebar 174 is stillwithheld from engaging with the disk 169 by the local circuit, formed asfollows: Starting at earth 208, through brush 207 and commutator-strip201 by wire, as shown, to magnet 172, thence by wire, as shown, toprojecting arm 178, thence by contact-point 189, with which it is inconnection by wire, as shown, to contact-stud 146 at frame 1, and thencethrough armature 144 to battery 148 and earth 149. The connection of anyother main line with this particularv local sub-station circuit througha corresponding set on its IOO IIO

frame 1b is prevented at the same time by the insulated projecting arm177 pressing the contact-point 187 away from the contact-point 138, thusbreaking the wire connection to the earth at 162, Fig. 4, (frame 1X,)which is common to all these sets X on the frames 1b.

Interruption to station C at New York end is prevented as follows: Thearmature-bar 9, with its projecting arms, having moved away from thehome set at T, as shown at frame l, Fig. 3, the contact-point 16 of thatset is no longer pressing against the contact-point 15 and theconnection with the earth at 52 is thereby broken, preventing any othermainline circuit from being completed through that frame until the bar 9again returns to the home set T, which will not be until thecommunication then in progress is concluded and the apparatus comes toits normal condition through the action of the operators at stations Cand D, as hereinafter described.

Having now shown how station C at New York has established communicationby main wire with station E through station D at Boston and also howboth these stations are protected from interruption, it will now beshown how the operator at E cuts out the other sub-stations on the samecircuit as himself without disturbing the apparatus at frame 1X, Fig. 4.The main line circuit has been shown to pass through magnet 155 at frame1X, Figs. 2 and 4, thereby energizing it and withdrawing its armature150 from stop 152 against stop 153, Fig. 4, thus breaking the circuit ofbattery 141, formed through battery 161 and to earth at sub-station E,and so preventing any action at the sub-station from affecting theapparatus at frame 1X, Boston, but leaving the position of armature-bar120 undisturbed, being held by the action of the local circuit ofbattery 141 through magnet 118. The connection of the armature 150,however, with the stop 153 completes the circuit of the battery 161through the coarsewound magnet 154 and down to station E through battery255. It will be noticed, however, that these batteries 161 and 255 havetheir poles opposed, and consequently there is no current owing on thiscircuit and energizing the magnets 241 at E and 220 at D. The stationsupon this Boston sub-circuit are now in condition to answer thesignal-call from the distant or New York station without disturbing theapparatus at theirframe 1X, as follows: Assumin g that the signal callsfor E, the operator at E immediately places the switch 2 2 in positionto touch both the studs 233 and 234, as shown in Fig. 4. This at oncecuts out all the other stations on this particular local circuit,securing entire privacy of communication between the operator at E andthe distant station that has signaled him, as will be now explained.Vhile this switch 232 was open the two batteries 161 and 255 wereopposing and neutralizing each other, as already explained; but as soonas the said switch is placed on said two studs 233 and 234 a ground isprovided at 243 for both-for battery 255 through stud 237, insulated end236 of armature-bar 235, by wire to stud 233, over switch to stud 234,by wire to contactpoint 23S, (situated on but insulated from bar 235,)to stud 239, and thence by wire to ground 243. Battery 161 completes itscircuit as follows: By wire, as shown, from the earth to switch 157,thence through magnet 154 to stud 153 and armature 150 to battery 161,thence by wire, as shown, to station D, through magnet 220 and rheostat221, to switch 232 at E, to stud 234, and thence to ground at 243 bysame connections as battery 255. It is evident, therefore, that whereasthe two batteries 161 and 255 were opposing and neutralizing each otherpreviously to the switch 232 being placed upon the two studs 233 and234, directly said switch is so placed the current of battery 161. ispassed through. and energizes the magnet 220 at D, thereby drawing downthe armature-bar'213, and so breaking the connection of thecontact-points 216 and 217 and forming connection between thearmature-bar 213 and stud 213, and manifestly in the same way passingthrough the corresponding magnets ot' any other sub-stations till itgets a ground at 243; but the current of battery 255 at E (the stationsignaled and where the switch 232 has been placed upon the studs)passes, as shown, around the magnet 241, thereby leaving the armaturebarin position unchanged, as shown, to form connections and effect theresults just described, and also to prevent the shunting of theoperatilig-instruments at station E.

The result of the armature-bar 213 being drawn down inthe oth ersub-station, as shown at D, Fig. 4,is twofold: First,it prevents theoperator there from accomplishing anything by any manipulation of hisswitch 210, as will be seen by inspection, and, secondly, it completelycuts out the operati11g-instruments at that station from the main-wirecircuit as follows: Corning from brush 140 at the main (Boston) officeit is diverted from the instruments at D by the avenue offered it by thewire running to the armature-bar 213, which being now in contact withthe stud 213 the shunt round the operatinginstruments completed and thecurrent is so carried direct to E, and passes through theoperating-instruments there to ground 254, as shown.

In the foregoing description I have described the operation ot` thesystem where the sub-station signaled is the last one of two or more ona single local circuit. 1n the event ot' the station called beingsituated between the main ofce and the last station on the local circuitit is evident that the switch 232 would not be closed, and the battery255 would thereby have to go through magnet 241 to get a ground andwould draw down the armature-bar 235, putting station E into thecondition shown at D in Fig. 4.

Assuming the desired communication between C and E to be ended, therelease of the IOO ITO

apparatus and its return to its normal condition, ready for use again,is effected as follows: The operator atE opens the key 249 and throws 0Eswitch 232. He then replaces the switch 232 again for a few seconds andthen leaves it disconnected. He then closes the key 249 again, and theapparatus is ready for the next call. The operator at C opens his key103 and throws oif and then on and ott' again his switch 42. The resultof these movements is as follows: Vhen the operator at C throws oit' hisswitch 42 from stud 44, the circuit of battery 31 is'broken and themagnet 7 is cle-energized and the stud 10 engages with the revolving`disk 5, thereby` rotating the projecting arms 11, 12, and 13 until thesegment commutator-strip 24 comes round to form contact with the brushes27 and 28, when the projecting arms will be opposite the home set T ofthe contact-points, as at iirst. Directly these brushes 27 and 28 comein contact with the comInutator-strip 24 the local battery 30 againautomatically energzes the magnet 7 and the stud 10 is again freed fromthe disk 5, thereby stopping the rotation of the projecting arms at thehome set, as desired, and leavin g them in contact with thecontact-points 14 and 16, and with the strip 16 pressing against strip15, Fig. 1, as previously described.

The frame 1bx at Boston is returned to its home set as follows: The key249 at E being opened -the main-line circuit is broken, the throwing offofthe switch 232 from the studs 233 and 234 de-energizes magnet 154, andthere is consequently no current flowing through either ot' themagnet-coils 154 and 155, so that the armature 150 is withdrawn againstthe stop 152, re-forming the circuit of battery 161 through magnet 143to earth at 142. The subsequent throwing on again of switch 232 at Egrounds the battery 161 and energizes magnet 143, thereby drawingarmature 144 from stop 146, breaking the circuit of battery 148 throughcontact point 189 (frame 1W) and projecting arm 178 and magnet 171,thereby de-energizing magnet 172 and allowing stud 175 to engage withdisk 169, rotating the projecting arms till opposite the home set Y,when the commutator-strip 196 will come in contact with brush 202,whereupon the battery 195 again automatically energizes magnet 172,withdrawing the stud from the disk and bringing the apparatus to rest,with the projecting arm 176 lupon the contact-point 181 and pressing itagainst 180 and arln 171 pressing contact-point 184 against 183, therebyleaving the whole apparatus again in position for use as at first, asshown at 1b, Fig. 2.

We will now assume that communication is desired between C at New Yorkand H, Figs. 5 and 6, which is a substation situated on a localcircuithaving more than one sub-station upon it, at a distant city wherethe number ot' sub-stations is so great as to render it necessary toincrease the capacity of the appa- Vpoints 354 and 355 to earth at 363.

ception of the sets of contact-points representing substation circuitsin excess of the number that can be conveniently accommodated on frame1C. Fig. 5 represents the apparatus at the distant city in its normalposition at rest. Fig. 6 shows the same in use. Framesl and 1c of Figs.5 and 6 are in every respect similar to frames 1 and 1hX of Fig. 4, withthe exception that frame 1c of Figs. 5 and 6 is equipped with as manydifferent sets of contact -points as there may be auxiliary switches F,the contact-points of these sets being so arranged as to form therequired connections with the auxiliary switches F. A convenient form ofthese additional sets is shown at Z on frame 1, Figs. 5 and 6, and areplaced upon the frame next in succession to the home set.

The operation of forming connection with station H by means of thisauxiliary switch F is as follows: The operator at Ofirst places a plugin the auxiliary-switch hole of his dialplate representing F. He thenputs another plug in the sub-station hole representing the local circuitupon which H at the distant city is located. He then proceeds aspreviously described. The result' is that the moving parts at frame 1Cwill be set in motion in the same manner as hereinbefore described, andas soon as the arm of the dial at C comes into contact with the pluginserted in the auxiliary-switch hole the apparatus at frame 1c stops,in the manner previously described, at the set of contact-pointsrepresented by the auxiliary-switch hole in the dial in which the plughas been inserted, as shown in Fig. 6, with the projecting arms incontact with the set of contact-points Z. The result of this is that alocal circuit is formed as follows: From earth 342 to brush 341 andcommutator-strip 335 through magnet 308 to project-ing arm 315, thencethrough contact-point 323 to battery 362 at switch F, and thence bycontact- This circuit so formed energizes magnet 308 at 1, therebyholding the apparatus at rest in this position. At the same time themain-line circuit is continued by brush 338 and commutator-strip 332 offrame 1c to projecting arm 313, contact-point 322, and thence by Wire,as shown, to brush 371 at F, and so by commutator-strip 367 to andthrough magnet 345, thence by wire, as shown, to projecting arm 350, andthence by contact-point 353 to earth at 363, as shown in Fig. 5. Magnet345 is thereby energized and neutralizes magnet 346, which is locallyenergized by battery 372, as shown, thereby allowing the stud 349 toengage with the rotating disk 343. The projecting arms are thereforecarried round in the manner before described until the arm at the dialat C forms connection with the plug inserted in the hole representingthe sub-station circuit upon which H is located, when IIO the projectingarm automatically stops in the same way, as heretofore explained, andthe connection is formed as shown in Fig. G. Station I-I can now besignaled from C at the other end, whereupon he proceeds as cxplained indescription ot operation at station E.

I will now describe the manner in which the apparatus at frames lc and1d are brought back to their normal position after communication isfinished. rlhe operators at the stations C and H proceed in the same wayas before described, with the following results: The rst thing to bedone is to break the local circuit of battery 296, which is holding theprojecting arms at frame ld, by energizing magnet 346. This isaccomplished in the same way as described in the operation ot the sameparts in Fig. et--viz., by the withdrawal of armature 292 from stop 295.The moving apparatus at frame l.d then automatically revolves till itreaches its home point at IV in the same manner as previously described,when it stops; -but at the moment ot' reaching its home set theprojecting arm 350 presses contact-point 355 away from contact-point354, thereby breaking the circuit of battery 362,which has beenenergizing magnet 308 at frame l", permitting the stud 311 to engagewith the disk 305, thereby automatically starting the apparatus at thisframe also on its return to its home point at Y, where it willautomatically stop, as before described. rlhe apparatus is now again inposition for forming a new connection when desired. The term series asherein used is intended to cover two or more.

Having thus described my invention, I claim- 1. In a system oftelegraphy, the combination of a transmittingr local-subscriberscircuit, a main line, a receiving local-subscribers circuit having anumber ot subscribers stations arranged thereupon in series and havingapparatus and connections by means of which any particular subscribercalled may cut out all other subscribers on the same localsubscriberscircuit, an automatic switch actuated from the transmittinglocal-subscribers circuit, and controlling circuit connections betweensaid transmitting local circuit and main line, and a second automaticswitch actuated by current on the main line and controlling circuitconnections between the main line and the receiving local-subscriberscircuit, substantially as described.

2. In a system of telegraphy, the combination of a transmittinglocal-subscribers circuit, a main line, a series of receivinglocalsubscribers circuit, an automatic switch actuated from thetransmitting local-subscribers circuit, and controlling circuitconnections between said transmitting local circuit and the mainline,and a second automatic switch actuated by current ou the main line andcontrolling circuit connection between the main line, a local auxiliarycircuit, and an auxiliary automatic switch actuated by current on saidauxiliary circuit, and controlling circuit connections between theauxiliary circuit and the receiving local-subscribers circuit,substantially as described.

In a system of telegraphy, the combination ot a transmittinglocal-subscribers circuit, a main line, a series of receivinglocalsubscribers circuits, an automatic switch actuated from thetransmitting local-subscribers circuit, and controlling circuitconnections between said transmitting local-subscribers circuit and themain line, a second automatic switch actuated by current on the mainline, and controlling-circuit connections between the main line and aseries ot' local auxiliary circuits, and an auxiliary automatic switchfor each auxiliary circuit actuated by current on the latter, andcontrolling circuit connections between the auxiliary circuit with whichit is connected and the appropriate local-subscribers circuit,substantially as described.

4. In a system of telegraphy, the combination ot' a series oftransmittinglocal-subscribers circuits, a receiving local-subscriberscircuit,a main line common to all local-subscribers circuits, a seriesot' automatic switches,one for each transmitting local-su bscriberscircuit, each actuated from its appropriate transmittinglocal-subscribers circuit, and controlling circuit connections betweensaid transmitting local circuit and the main line and cutting out allother transmitting local-subscribers circuits from said main line, and asecond automatic switch actuated by impulses transmitted over the mainline from a distant transmitting local circuit, and controlling-circuitconnections between the main line and the receiving local-subscriberscircuit, substantially as described.

5. In a system of telegraphy` the combination of a transmittinglocal-subscribers circuit, a series ot main lines, a receivinglocalsubscribers circuit, an automatic switch actuated from thetransmitting local-subscribers circuit, and controlling circuitconnections between the transmitting local-subscribers circuit and anyone of the main lines that happens to be idle and in order, a secondautomatic switch actuated by impulses transmitted over theautomatically-selected main line from the distanttransmitting-subscribers7 circuits and controlling circuit connectionsbetween said main line and the receiving local-subscribers circuit,substantially as described.

G. In a system of telegraphy, the combination of a series oftransmitting local-subscribers circuits,a receivinglocal-subscriberscircuit, a series of main lines common to all the local-subscribers7circuits, an automatic switch for each transmittinglocal-subscriberscircuit actuated from said circuit, and controlling circuit connectionsbetween the same and one or the other ot the main lines and cutting outall other transmitting local-subroo IIO

scribers circuits from said selected main line, a second automaticswitch actuated by impulses transmitted from the distant transmittinglocal-subscribers circuit over the particular main line being at thetime utilized, and controlling circuit connections between said mainline and the receiving local-subscribers circuit, substantially asdescribed.

7. In a system of telegraphy, the combination of a transmittinglocal-subscribers circuit, a series of receiving local-subscriberscircuits, a series of main lines common to all the local-subscriberscircuits, an automatic switch actuated from the transmittinglocalsubscribers circuit, and controlling circuit connections betweensaid transmitting local circuit and one or the other ot' the main lines,and a second automatic switch actuated by impulses transmitted from thedistant transmitting local-subscribers7 circuit over the selected mainline, and controlling circuit connections between the particularmainline being at the time utilized and one or the other of the seriesof receiving local-subscribers circuits, substantially as described.

8. In a system of telegraphy, the combination of a series oftransmitting localsubscribers circuits, a series of receivinglocalsubscribers circuits, a series of main lines common to all thelocal-subscribers circuits, an automatic switch apparatus for eachtransmitting local-subscribers circuit actuated from said circuit, andcontrolling circuit connections between the same and one or the other ofthe series of main lines and cutting out all other transmittinglocal-subscribers circuits from said selected main line, and a secondautomatic switch apparatus actuated by impulses transmitted from adistant transmitting local-subscribers circuit over the particular mainline being at the time utilized, and controlling circuit connectionsbetween said main line and one or the other of the receivinglocal-subscriber circuits,substantiall y as described.

9. In a system of telegraphy, a series of transmitting local-subscriberscircuits, a series of main lines, a series of receiving localsubscriberscircuits, an automatic switching apparatus for each transmittinglocal-subscribers circuit, operating upon a signal from a subscriber onits particular local circuit toconnect the said circuit with one of themain lines that happens at the time to be idle and cutting out all othertransmitting local-subscribers circuits from said selected main line,

a second automatic switching apparatus op-v erated by the current on themain line to connect said main line with any predetermined receivinglocal-subscribers circuit, and an apparatus at the transmittinglocal-subscribers station for automatically arresting said secondswitching apparatus to make connection with said predetermined receivinglocal-subscribers circuit, so that communication between the distantlocal subscribers may be carried on, substantially as described.

l0. In a system of telegraphy, a series of transmittinglocal-subscribers circuits, a series of main lines, a series ofreceiving localsubscribers circuits, an automatic switch apparatus foreach transmitting local-subscribers circuit, operating upon a signalfromany subscriber on `said transmitting local-subscribers circuit toconnect said last-mentioned circuit with one of the main lines whichhappens at the time to be idle and to cut out all other transmittinglocal-subscribers circuits from the main line so selected, a secondautomatic switching apparatus operated by the current on the main line,having a series of movable contacts and a series of stationary sets ofcontacts corresponding in number to the number of receivinglocal-subscribers circuits, said series of movable contacts operating tocause an electrical impulse to be sent back to the transmittinglocal-subscribers station each time a set of contacts belonging to areceiving local-subscribers circuit is touched and passed, and anapparatus at the transmitting local-subscribers station actuated by theimpulses aforesaid and operating to arrest said second automaticswitching apparatus when at the point for connection with thepredetermined local-subscribers circuit, so as to enable communicationto be had between the transmitting local subscriber and the saidpredetermined remote receiving subscriber, substantially as described.

l1. In a system of telegraphy, a transmitting` local-subscriberscircuit, a main line, a series of receiving local-subscribers circuits,an automatic switching apparatus for the transmitting local-subscriberscircuit, operating upon a signal from a subscriber on said local circuitto connect said circuit with the main line and throw a current-generator on said main line, a second automatic switching apparatusconnected to the main line and operated by the current thereon andhaving a movable set of contacts and a series of sets of stationarycontacts corresponding in number to the number of receivinglocal-subscribers7 circuits, said movable set of contacts operating asit touches and lpasses each successive set ot' stationary contacts toground the main line and send an electrical impulse over the same to thedistant-transmitting localsubscribers station, and an electro-mechanicalapparatus at the transmitting local-sub-v scribers station, adapted toadvance step by step under the aforesaid impulses and when thestationary set of contacts belonging to the predetermined receivinglocal-subscribers circuit desired to be connected is reached by themovable set of contacts to afford a new path for the main-line current,which changes the electrical condition of the main circuit and causesthe switching apparatus to be arrested while communication is being hadbetween the distant local-subscribers station.

IOO

IIO

12. In a system of telegraphy, a series of transmittinglocal-subscribers circuits, a series of main lines, a series otreceiving localsubscribers7 circuits, an automatic switch apparatus foreach transmitting local-subscribers circuit, operating upon a signalfrom any subscriber on said local transmitting-subscribers circuit toconnect said last-mentioned circuit with one of the main lines whichhappens at the time to be idle and to cut out all other transmittinglocal-subscribers circuits from the main line so selected, a secondautomatic switching apparatus connected to and operated from the mainline and having a movable set ot' contacts, and a series of sets ofstationary contacts corresponding in number to the number ot receivinglocal-subscribers circuits, said movable set of contacts operating as ittouches and passes each successive setI of stationary contacts to groundthe main line and send an impulse to the transmitting local-subscribersstation, and an electro-mechanical apparatus at thelast named station,which advances step by step in response to the aforesaid electricaliinpulses until the set of contacts ot' the predetermined receivinglocal-subscribers circuit is reached, whereupon a new path for themain-line current is aiorded, which changes the condition of saidmain-line circuit and causes the arrest of the movable set of contactsof the switching apparatus, substantially as described.

13. In the herein-described system of telegraphy, the combination of amain line, a transmitting local-subscribers circuit, an automaticswitching apparatus by which said transmitting local-subscribers circuitis connected to the main line, consisting, essentially, of the framebearing the sets of stationary contacts, the continuously-rotating shafthaving the perforated disk secured thereto, the sleeve mounted upon saidshaft, carrying the armature bar provided with contacts, as described,the electro-magnet, the spring and the commutators, the battery andcircuit connections for holding the armaturelever normally disengagedfrom the rotating disk, the battery and circuit connections fordisengaging the armature-lever from the disk when in position forconnection with the main line, and the hand-switches and connectionsunder control of the operator at the transmitting local-subscribersstation, all arranged and operating substantially as described.

14. In the herein-described system of telegraphy, the combination of aseries of main lines, a transmitting local-subscribers circuit, andautomatically switching apparatus by which said transmittinglocal-subscribers circuit is connected to one or the other of the mainlines, said switching apparatus consisting, essentially, of the framebearing the sets of stationary contacts, a continuously-rotating shafthaving the perforated disks secured thereto, the sleeve mounted uponsaid shaft,

carrying the armature-bar provided with contacts, as described, theelectro-magnet, the spring and the commutators, the battery andconnections for holding the armature-lever normally disengaged from therotating disks, the battery and connections for disengaging thearmature-lever from the disk when in position for connection with one orthe other of the main lines, and the hand-switches and connections undercont-rol of the operator at the transmitting local-subscribers station,all arranged and operating substantially as described.

15. In the herein-described system of telegraphy, the combination of aseries of main lines, a series ot' transmitting local-subscrilr erscircuits, and a series of automatic switching apparatus, one for eachtransmitting-subscribers7 circuit, each consisting, essentially, of aframe bearing the sets of stationary contacts, a continuously-rotatin gshaft having the perforated disks secured thereto, the sleeve mountedupon said shaft, carrying the armature-bar provided with contacts, asdescribed, the electro-magnet, the spring and the conimutators, thebattery and connections for holding the armature-lever normallydisengaged from the rotating disks, the battery and connections fordisengaging the armature-lever from the dislc when in position forconnection with one or the other of the main lines, and thehand-switches and connections under control oi the operator at thetransmitting local-subscribers station, all arranged and operatingsubstantially as described.

1C. In the herein-described system of telegraphy, the combination, withthe main line and its battery, of the series of receivinglocalsubscribers circuits and the automatic switching apparatus forestablishing connection between said rnain line and one or the other ofthe receiving local-subscribers circuits, said switching apparatusconsisting, essentially, of the frame, with its series of sets ofcontacts corresponding to the number of receiving local-subscriberscircuits, the constantly-rotating shaft bearing the perforated disk, thesleeve mounted upon said shaft, carrying the armature-lever providedwith contacts, as described, the electro-magnets, one of which isenergized by the current of the main line and the other by the currentof a local battery, the retracting-spring, and the commutators, with thecommutator-brushes and circuit connections arranged and operatingsubstantially as described.

17. In the herein-described system of telegraphy, the combination, witha main line, of a transmitting local-subscribers circuit and automaticswitching apparatus, by which said transmitting local-subscriberscircuit is connected to the mainline, consisting of the frame with itssets of stationary contacts, the continuously-rotating shaft having theperforated disk secured thereto, the sleeve mounted upon said shaft,carrying the armature-bar provided with contacts, as described, theelec- IOO IIO

tro-magnet, the spring and the commutators, the battery and circuitconnections for holding the armature-lever normall)T disengaged from therotating disk, the battery and circuit connections for disengaging thearmature-lever from the disk when in position for connection with themain lines, and the handswitches and connections under the control,

of the operator at the transmitting local-subscribers station,thebattery on the main line, the series of receivingr local-subscriberscircuit, the automatic swinging apparatus for establishing connectionbetween the mainline and one or the other of the receivinglocalsubscribers circuits, said switching apparatus consisting,essentially, of the frame with its series of sets of contactscorresponding to the number of receiving local-subscribers circuits, theconstantly-rotating shaft bearing the perforated disk, the sleevemounted upon said shaft, carrying the armature-lever provided withcontact-s, as described, the electro-magnets, one of which is energizedby lthe current of the main line and the other by the current of a localbattery, as described, the retracting-spring and the commutators withcommutator-brushes and circuit connections, as described, and theapparatus at the transmitting local-subscribers station for effectingthe arrest of the switching apparatus and establishing connection withthe desired receiving local-subscribers7 circuit, consisting of theperforated dial, the metallic stud, the movable arm, the electro-magnet,and means for advancing the arm step by step by impulses sent over themain line, as described, and the rheostat and switches and circuitconnections, substantially as set forth.

1S. In the herein-described system of telegraphy, the combination,withthe series of main lines, of the series of transmittinglocal-subscribers circuits, the series of receiving localsubscriberscircuits, a series of automatic switching apparatus, one for eachtransmitting local-subscribers circuit, by which any one of saidtransmitting local-subscribers circuits may be connected to an idle mainline, said automatic switching apparatus consisting of the frame andsets of stationary contacts, the continuously-rotating shaft having theperforated disk secured thereto, the sleeve mounted upon said shaft,carrying the armature-bar provided with contacts, as described, theelectro-magnet, the spring and the commutators, the batteries andcircuit connections, as described, means such as described for cuttingout all the other transmitting local-subscribers circuits from saidselected main line, the 'automatic switching apparatus for establishingconnection between the main line and one or the other of the receivinglocalsubscribers circuits, said switching apparatus consisting,essentially, of the frame with the series of sets of contactscorresponding to the number of the receiving local-subscribers circuits,a constantly-rotating shaft bearing the perforated disk, the sleevemounted loosely upon said shaft, carrying the armature-lever andprovided with contacts, as described, the electro-magnets and retractilespring for operating said armature-lever and the commutator-brushes andcircuit connections, as described, and the apparatus at the transmittinglocal-subscribers station for effecting the arrest of the distantswitching apparatus and establishing connections between the main lineand the desired receiving local-subscribers circuit, consisting of theperforated dial, metallic stud, movable arm, the electromagnet, andmeans for advancing the arm step by step by impulses sent over the mainline, as described, and the rheostat, handswitches, and circuitconnection, substantially as set forth.

JAMES G. SMITH. Witnesses:

GEORGE W. Cov, WM. LEE DARLING.

